The present invention relates to a safety latch and, more particularly, to a safety latch utilizing a movable latch bolt which is biased in the open or unlocked position to preclude accidental movement of the latch bolt into the locked position.
Bolt latches (sometimes called barrel bolts or slide bolts) have been well known for many years. Such devices are frequently used to lock or bolt doors, windows, containers, cabinets, etc. The latch bolt has been favored for many such applications because of its simplicity and ease of installation. Typically, such latches are used in situations where key locks are not necessary such as at the interior side of a door. Thus, for example, where a latch bolt is used in the interior, it is actuated after entrance as additional security against unwanted entry by others.
Latch bolts of the type heretofore known generally included a bolt slidable through a housing and extendible into a bolt keeper located and secured to the threshold, door jam or wall adjacent to the door. One difficulty encountered by such latch bolts is that the bolt may be accidentally moved into the locking position by vibration which may occur, for example, upon closure of the door, with the unfortunate result of causing the door to be inadvertently locked in the closed position leaving a person without access to the interior.
Various constructions and designs have been proposed for latch bolts of the type just described including some which have utilized springs. However, such devices have frequently involved excessively complicated construction and/or numerous parts which cause such devices to be difficult or expensive to manufacture or use. For example, where springs are positioned around the bolt fouling of the latch can occur if sand, dirt or other debris enters the mechanism and plugs the latch. Latches with weighted bolts have also been suggested but such latches are not able to be used in all positions. As a result these and other disadvantages, such latches are not commonly available in the marketplace.
The present invention provides a simple and efficient safety latch of the latch bolt type which avoids the above-described disadvantages and which is simple, efficient, economical to manufacture and can be installed in any position, e.g., vertical, horizontal, etc.